<template>
  <el-breadcrumb class="app-breadcrumb" separator="/">
    <transition-group name="breadcrumb">
      <el-breadcrumb-item v-for="(item, index) in levelList" :key="item.path">
        <span
          v-if="item.redirect === 'noRedirect' || index == levelList.length - 1"
          class="no-redirect"
        >
          {{ item.meta.title }}
        </span>
        <a v-else @click.prevent="handleLink(item)">{{ item.meta.title }}</a>
      </el-breadcrumb-item>
    </transition-group>
  </el-breadcrumb>
</template>

<script setup>
const route = useRoute();
const router = useRouter();
const levelList = ref([]);
function getBreadcrumb() {
  // only show routes with meta.title
  let matched = route.matched.filter(item => item.meta && item.meta.title);
  const first = matched[0];
  // 判断是否为首页
  if (!isDashboard(first)) {
    matched = [{ path: '/', meta: { title: '首页' } }].concat(matched);
  }

  levelList.value = matched.filter(
    item => item.meta && item.meta.title && item.meta.breadcrumb !== false
  );
}
function isDashboard(route) {
  const name = route && route.name;
  if (!name) {
    return false;
  }
  return name.trim() === 'Index';
}
function handleLink(item) {
  const { redirect } = item;
  if (redirect) {
    return router.push(redirect);
  }
  if (item.path === '/') {
    return router.push('/');
  }
  const firstPageName = getFirstChildrenName([item]);
  if (firstPageName) router.push({ name: firstPageName });
}

function getFirstChildrenName(routes) {
  for (let i = 0; i < routes.length; i++) {
    const ROUTE_ITEM = routes[i];
    if (ROUTE_ITEM.hidden) continue;
    if (ROUTE_ITEM?.children?.length) {
      const firsteName = getFirstChildrenName(ROUTE_ITEM?.children);
      if (firsteName) return firsteName;
    } else {
      return ROUTE_ITEM.name;
    }
  }
}

watchEffect(() => {
  // if you go to the redirect page, do not update the breadcrumbs
  if (route.path.startsWith('/redirect/')) {
    return;
  }
  getBreadcrumb();
});
getBreadcrumb();
</script>

<style lang="scss" scoped>
.app-breadcrumb.el-breadcrumb {
  display: inline-block;
  font-size: 14px;
  line-height: 50px;
  margin-left: 8px;

  .no-redirect {
    color: #97a8be;
    cursor: text;
  }
}
</style>
